Which of the following numbers is a multiple of 4? ${70,88,91,111,113}$
Explanation: The multiples of $4$ are $4$ $8$ $12$ $16$ ..... In general, any number that leaves no remainder when divided by $4$ is considered a multiple of $4$ We can start by dividing each of our answer choices by $4$ $70 \div 4 = 17\text{ R }2$ $88 \div 4 = 22$ $91 \div 4 = 22\text{ R }3$ $111 \div 4 = 27\text{ R }3$ $113 \div 4 = 28\text{ R }1$ The only answer choice that leaves no remainder after the division is $88$ $ 22$ $4$ $88$ We can check our answer by looking at the prime factorization of both numbers. Notice that the prime factors of $4$ are contained within the prime factors of $88$ $88 = 2\times2\times2\times11 4 = 2\times2$ Therefore the only multiple of $4$ out of our choices is $88$. We can say that $88$ is divisible by $4$.